This is the mail archive of the
mailing list for the GDB project.
Re: RFC: Mostly kill FRAME_CHAIN_VALID, add user knob
- From: Daniel Jacobowitz <drow at mvista dot com>
- To: gdb-patches at sources dot redhat dot com
- Date: Sat, 4 Jan 2003 20:42:13 -0500
- Subject: Re: RFC: Mostly kill FRAME_CHAIN_VALID, add user knob
- References: <20021226191541.GA8483@nevyn.them.org> <3E149438.firstname.lastname@example.org>
On Thu, Jan 02, 2003 at 07:34:16PM +0000, Andrew Cagney wrote:
> >Pretty gross, neh? Well, file vs. func is merely a question of whether we
> >stop at main or not, so I added "set backtrace-below-main" in order to let
> >the user choose. Generic vs. not is a question of dummy frames, and the
> >generic versions work with non-generic dummy frames, so there's no reason
> >for that distinction earlier. It won't harm those three m68k targets (if
> >they still work) to use a more comprehensive frame_chain_valid. And the
> >five more specific ones up above can be retained, since they are only
> >_additional_ checks. I'm not entirely convinced that the Interix one is
> >necessary but I left it alone.
> >So, after this patch we have FRAME_CHAIN_VALID as a predicated function
> >only five architectures define; everything else just uses the new
> >frame_chain_valid () function, which is a more general version of
> >I'm more confident I got the texinfo right this time :) I tested the patch
> >and the new functionality on i386-linux and arm-elf, to make sure I got the
> >details of FRAME_CHAIN_VALID_P () right.
> >I'll look to commit this in January, if no one has any comments. Andrew,
> >would you rather this went in frame.c? Since a purpose of that file seems
> >to be moving things from blockframe.c to it...
> Much of this is superseeded by the frame overhaul - in particular the
> introduction of frame_id_unwind(). The new code doesn't even call frame
> chain valid!
> Perhaphs wait for the attached [wip] to be committed and then tweak that
> to match your proposed policy (we can then just deprecate
> FRAME_CHAIN_VALID_P :-). However, making the change in parallel
> wouldn't hurt.
> Looking at my WIP, I'll need to tweak the code segment:
> + prev_frame->pc = frame_pc_unwind (next_frame);
> + if (prev_frame->pc == 0)
> + /* The allocated PREV_FRAME will be reclaimed when the frame
> + obstack is next purged. */
> + return NULL;
> + prev_frame->type = frame_type_from_pc (prev_frame->pc);
> so that it checks for where the PC resides and abort accordingly.
> The attached is WIP since I still need to see it working once :-)
[Small wonder if you haven't pushed the call to FRAME_CHAIN_VALID
somewhere... that's the same sort of thing that confuses me about all
of your frame changes...]
I've chosen to commit it instead, since your WIP isn't ready, and since
you understand better than I do how it'll fit into the New Order.
MontaVista Software Debian GNU/Linux Developer